预制沟道缆线管廊工作井设缝形式对受力性能影响

工作井作为沟道缆线型管廊的主要组成部分，具有电缆敷设作业、设置电缆中间接头和电缆引出等多种功能。为提高现场施工效率，工程中工作井大多采用加工厂分块预制、现场拼装形式，设缝形式对工作井整体刚度和承载力影响较大，不合理设缝形式将造成结构整体受力性能下降。研究建立一字型、T字型和十字型三种常见沟道管廊工作井有限元模型，针对纵横两种设缝形式分别进行抗弯和抗弯剪受力性能分析，同时与整体现浇工作井进行内力和变形对比。计算结果表明：纵向设缝下一字型、T字型、十字型工作井抗弯刚度分别下降48%、51%和44%；横向设缝下抗弯刚度分别下降34%、32%和26%。研究成果可对预制沟道管廊工作井分块拼装设计和工程应用提供参考。

Analysis on the influence of joint form of working shaft of prefabricated trench cable gallery on mechanical performance

As the main part of the trench cable gallery, the work well has many functions, such as cable laying, setting cable intermediate joint and cable lead-out. In order to improve the field construction efficiency, most of the work wells in the project are prefabricated by processing plants and assembled on site. The form of split has a great influence on the overall stiffness and bearing capacity of the work well, and unreasonable form of joint will cause the overall mechanical performance of the structure to decrease. Finite element models of three common channel and gallery work wells, i.e. one-type, T-type and cross-type, were established to analyze the bending and shear behavior of longitudinal and transverse joints respectively, and to compare the internal force and deformation with the integral cast-in-situ work well. The calculation results showed that the stiffness under longitudinal joints of Ishaped, T-shaped and cross shaped work wells decreased by 48%, 51% and 44% respectively. The bending stiffness under transverse slits decreases by 34%, 32% and 26% respectively. The research results can provide reference for the sectional assembly design and engineering application of the prefabricated trench gallery work well.